Syphilis is a chronic infectious disease, which dates back to the XV century and is caused by the spirochete treponema pallidum, capable of invading the central nervous system in any of its stages- Its incidence has increased in parallel to the HIV/AIDS pandemic, and the synergism between both pathologies is such. that it has become a public health problem in recent years. Here we present the case of a 31-year-old female patient, who consulted for headache associated with decreased visual acuity and provided an unenhanced head CT showing hypodense lesions in both thalamic regions, serological tests for syphilis were reactive and those for HIV were not reactive. The brain MRI with spectroscopy was reported in favor of cerebral toxoplasmosis, which was later ruled out with a study of cerebrospinal fluid. Management with penicillin G sodium IV for 6 weeks was indicated, achieving complete imaging resolution of her lesions.